Aver

Aver \uh-VUR\ , transitive verb;
1. To affirm with confidence; to declare in a positive manner, as in confidence of asserting the truth
2. Law: To assert, claim, or declare as fact

This word dates to the late 14th century and comes from Old French averer ("verify"), which is derived from Vulgar Latin *adverare ("make true, prove to be true"). The Latin word on which *adverare is based is verus, plus the prefix ad-, meaning "to". Verus means "true" and comes from Proto-Indo-European *weros-.
Verus is also the forebear of very along the following chain:
verus > verax > *veracus > verai > verrai > verray
Latin > Latin > Vulgar Latin > Old French > Anglo-French > Old/Middle English.

*For a refresher on Vulgar Latin: bonanza
*For a refresher on Proto-Indo-European: eke

Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Sunday, March 13
Etymologies come from the Oxford English Dictionary and/or Etymonline.com